Edge is changing the file extension of downloaded files, how can I stop this?

Whenever I download a file using Edge it changes the file extension to .stl it does this on all file types and can be quite confusing sometimes guessing what the extension should be, if I use a download manager the files download correctly.

I have a few programs installed with use the .stl file type for my 3D printer (Repetier Host & Simplyfy3D) but removing these doesn't correct the problem.